Vibration record and method of making the same



Aug.Y 12, 1941. J. H.VDE BOER ETAL VIBRATION RECORD AND METHOD OF MAKING THE SAME Filed June 26, 1937 APatented Aug'. 12, 19`41 MAKING THE SAME Jan Hendrik de Boer and Cornelis Johannes ADippel, Eindhoven, Netherlands, asslgnors, hy

mesne assignments, to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application June zo, 1937, serial No. 150,627 In Germany July 13, 1936 Claims.

Our invention relates to carriers for mechanically-recorded and optically-reproducible Vibration tracks particularly of the variable area type.

and to a method of making the same.

As our invention is particularly advantageous in connection with mechanical sound recording of the type described in the U. S. Patent 1,919,116 to James A. Miller, we shall describe the same in this connection.' However, the invention is not limited thereto but can `be usedv in connection with other types of mechanical recording in which an optically-reproducible vibration track particularly of the variable area type is produced.

In such mechanical recording it is general practice to use a carrier comprising a transparent recording or cutting layer and a thin covering layer which preferably contains metals y or metal compounds and which possesses, for example, at the time of recording, the degree of opacity required for the light employed inreproduction. During the recording, a cutting tool having a V-shaped cutting edge with an -apical angle of about 174 is vibrated perpendicularly to the surface of the carrier and in accordance with the vibrations being recorded,

to remove parts of this covering layer as well as parts of the cutting layer, and to thereby produce a vibration track which is transparent to the light used for reproductions. 'Such tracks have width variations which lare about forty times the amplitudes of the cutting tool and may be reproduced immediately without further treatment in the usual sound lrn apparatus, and have a quality of vreproduction which, up to the highest frequencies, generally considerably exceeds that of a photographically-recorded track.

When disregarding the advantage of immediate reproduction, it ispossible to use a carrier comprising at least two light-transmitting layers of which one is given the opacityrequlred for loptical reproduction only after the recording.

a vibration track which is mechanically recorded` in a light`trans`mitting vmaterial suited for this purpose, deleteriously laffected by scratches in its surface due. for example, to injury to the cutting edge'of the cutting tool, by other injuries I due to' irregularities inthe depth of the track,

and by dirt particles which adhere to the more or less sticky gelatin frequently used for the recording layer. These injuries and the irregularities in the depth ot the track cause irregular refraction of the rays of the reproducing light. whereas the noises produced thereby and ;by the dirt particles deleteriously influence the optical reproduction.

The' term optical reproduction as used herein is to be understood to also include optically copying the track onto another carrier. 4

It has been proposed to provide a carrier having a light-transmitting recording layer and a 'light-transmitting protective layer lying thereon with a. mechanically-recorded vibration record and to subsequently color the track with a coloring material which adheres only to the material of the vrecording layer at the track surface, for example with India ink. Such a method, however, has several disadvantages. For example, to f obtain a sufficient covering capacity it is generally necessary to utilize a comparatively concentrated solution of the vcoloring material, which necessitates the use of a rather thick layer which, particularly when a band-shaped carrier is used, will easily scale on. Even .with the use oi' black India ink, which permits the covering layer 'to be made rather thin, it frequently happens that this layer, after being dried, becomes loosened.

'I'he object of our invention is to overcome the above diilicuities, andto provide a simple and effective method for coloring the track portion ofA an optically-reproducible. variable-area mechanically-recorded"vibration record.

-In accordance with the invention we apply to the surface of a vibration track, which is bounded by a suitable thin protective layer, one or more substances which chemically react with one or more molecularlyor colloidally-dispersed sub-A stances being aiready present within or forming the recording layer to bring about the desired coloring of the track. I By' the term coloring of the track-is tobe -understood to mean that, after theabovemenabsorbs only the intra-redlight which is to be used for direct reproduction, only the ultra-violet light which is advantageously utilized in copying, or both these lights. For this reason the expressions blackened "impervious to light, colored, etc. as used hereinafter are to be considered in view of the type of light used for reproduction or copying.

, In accordance with the invention, the sub-A ystance which colors the track is produced by chemical reaction at the desired point, whereby v particularly sharply-denned boundaries between the colored and uncoloredportions of the carrier, i. e. between the track and its surroundings, are obtained. Furthermore, as at least one of .the substances producing the coloring is already present within or forms the material of the recording layer, when'the color-forming reaction' takes place, the coloring material will be embodied at least partly within this layer, and there will be a unitary connection between the colored material andthe recording layer. Because of this there Awill be no danger of the layer of colored material becoming loose from the carrier, for example, due to sharp bends in the conveying device during reproduction or copying.

The chemical reaction itself produces sharply-defined boundary between the track and its surroundings because when the constituent not yet present in the layer is being introduced therein by diffusion during the coloring process, this constituent is transformed by the chemical reaction and thus is consumed. Owing to this the coloring will not be produced at undesired portions as would be the case, for example, if a solution of coloring material were diffused into a layer `of gelatin. In the latter case the extent possible time and thus can be reproduced or copied almost'immediately, It is also possible to utilize a gas or vapor as the substance which is added to produce chemical reaction.

The methodaccording to the invention may be carried out while utilizing a so-called physical development of the track provided. For this purpose the recording layer of the track is provided with or made from one or more substances which, jointly with one or more substances added, form the basis of a chemical reaction rei sulting in coloration. In this case the substances act as nuclei which bring about the chemical reaction of the so-called physical development.

If the nuclei have to be formed by photochemical reaction, this photochemical formation of the nuclei canbe readily eifected by irradiation with suitable light after the trackhas been cut. By making the protective'layer impervious to the light utilized for this purpose, a .well-dened boundary between the track and its surroundings is obtained.

In another embodiment o f the invention, the coloring of the track is achieved by utilizing a substance with which it is possible to obtain a colored compound by a purely chemical agency, i. e. without making vuse of light-rays. This purely chemical method has theadvantage that an extremely thin homogeneous layer of colore ing material can be obtained by causing a molecular solution to react as one component with action product, is obtained. Accordingly, the.

coloring material is obtained and remains in a substantially grainless condition. 'I'his measure is particularly important if the track is cut with a chisel having a V-shaped cutting edge with an apical angle which is as obtuse as possible, e, g. of about 174.

In order that the invention may be clearly understood and readily lcarried into effect, we shall explain the same more fully with reference to the accompanying drawing, in which:

Figure 1 is an enlarged sectionaly view of a carrier and shows a V-shaped chisel cutting a track therein; l

Fig. 2 is a perspective View illustrating the method according to the invention; and

Fig. 3 is an enlarged sectional lview of a carrier illustrating the invention.

Referring to Figure l, a carrier i, which moves at a. constant speed during recording perpendicularly to the plane of the drawing, consists of a supporting layer 2 of transparent material, such as Celluloid, an intermediate or recording layer 3 of gelatin, and a thin protective layer f3. A cutting tool 5 having a V-shaped cutting edge with an apical angle of about 174 is vibrated in the direction of the double-headed arrow in accordance with the vibrations being recorded, to produce a track I5 having depth variations, and Width Variations which -are enlarged with respect to the depth variations.

If such a carrier is to be used as a negative, at least the surfaces .6 of track l5, which are laid bare in layer 3, must be colored. To insure sharp outlines or boundaries of track I5, it is evident that the layer of coloring material should not extend beneath the remaining Aportions of the protective layer d, i.ve. extend under the covering layer beyond edges l.

Thus it is preferable'to use a protective layer having such ay small capacity for absorbing and transmitting the coloring component applied after recording, that at least during the chemical reaction thiscomponent does not penetrate the surface of the covering layer. Thus, after the reaction, it is possible to clean the superfluously wetted portions of the covering layer in a simple manner, for example by wiping olf; so that the layer is still, for example, transparent to light.

The invention may be carried into eiect in various manners, some of which will be described in the following examples with reference to Figures 2 and 3.

Example 1,-The carrier shown inFig.' 2 is provided with a mechanically-recorded track l5, and-has a recording layer-3 of gelatinto which is added in homogeneous distribution, lead ace-v Vtate in asuitable concentration, for example-19 which produces at least at the surface of track l5; a layer of lead sulphide which makes the ltrack sulciently black. The lead acetate and Vthe ammonium sulphide concentrations must be suitably Ychosen with regard 'to each other. In this case the protective layer 4 should be of a material which is impervious tothe ammonium after recording, for example by applying anaqueous solution of this substance to the carrier, whereby the lead acetate penetrates only supercially into the surface of the gelatin layerv 3 that has been laid bare. Subsequently the carrier is treated with the ammoniumsulphide developer as in Example 1. In this case the materials of the protective layer may be thoselgiven in Example 1.

Although we have found that by the method of both the above-mentioned examples, very sharply-dened blackening of the track is obtained, in the method of Example 1 difculties sometimes arise due to an excessively'long treatment with the ammonium sulphide developer. 'Ihese difiiculties, however, are avoided by the method described in Example 2, ybecause the gelatin layer 3 is not provided with the lead acetate throughout its entire thickness, but the lead acetate solution penetrates only to a comparatively small depth. l

The method of Example 2 is diagrammatically illustrated in Figure 2'in which the track I5 is wetted with the lead acetate solution by means of a pad Il, for example of felt, and the track is immediately colored by means of a second pad I2 which contains, for example, ammonium sulphide developer with the result that the blackcolored track I6 shown in the figure is obtained. For the sake-of clearnessthe track I1 treated only with the lead acetate 'is indicated by shading.

Instead of using the lead acetate mentionedin Examples 1 and 2, we have found that good results are obtainedl by using other suitable lead.

salts, or other sulphide-producing metal salts, such for example as copper salts, mercurio and mercurous salts and nickel salts, and others. Instead of using a liquid developer such as ammonium or alkaline sulphide, similar results are tassium ferricyanide, and becomes colored by the transformation oi the indigo-white into the blue,

insoluble, collodally-dispersed indigo. The colf oration may also be eiected by means of oxygen gas or by atmospheric air. In the latter case the protective layer must of course be impervious to air, and' for this purpose the protective layer may consist, for example, of a polystyrol layer covered with a layer of nitrocellulose, or of a metal foil.

Example 6.-Co1oration of the track necessary vfor optical reproduction may also be obtained by coloring, after the recording, the material of the recording layer that has been laid bare, by the addition of a suitable substance. For example the recording layer, which advantageously consists of gelatin or of similar decomposed albuminous substances may be treated, after the recording, with an alkaline copper sulphate solution which results in a bluishto reddish-violet colored compound. l

Alternatively it is possible to treat the aminoacid, which is present in the gelatin layer and which is capable of coupling with a diazobenzene sulphonic acid solution, with this latter solution whereby after applying a 2 N. solution of soda to the track a colored compound is formed. In this case the protective covering layer may be Celluloid lacquer or nitrocellulose.

Example 7A.After a vibration track has been track is treated, for example, with an acid silver obtained by applying a gas current of hydrogen sulphide to the track provided with the sulphideproducing metal salts.

. Example 3.-'I'he method of Examples 1 and 2 may be carried out with the aid of other chemical reactions. For example, the substance present in the recording layer may be mercurous nitrate, whereas an ammonia solution may be utilized as the added component to produce in the tracks the so-'called black precipitate (NHzHgzNOs) Instead of using an ammonia solution, wet NH3 gas may be used.

Example 4.-If potassium ferrocyanide is used as the irst-applied component in the method of Example 1 or 2, a colored track may be obtained by applying avferric salt solution which acts on the potassium ferrocyanide to produce the colloidally-dispersed dark blue Prussian blue.

Example 5.-Indigo may be provided as the coloring material in the recording layer by the methods of Example 1 or 2. However, as this substance is insoluble in water, it must be taken up in the recording layer in another manner. This may be eiected by reducing' the indigo, for example with rongalite (sodium sulpho-oxylate) or with a hyposulphite salt (e. g. Naas-.04); the indigo being dissolved as indigo-white, and in this state is provided in the recording layer. The track is then treated with an oxidizing solution such as a solution '0f a ferri-salt, for example ponitrate solution and then with. an acid reducing agent, for example a citric acid-methol solution to eiect physical development, with the result that only area 9 of the recording layer is blackened. As the portions I0 of the recording layer located outside the area 9 have not been exposed and therefore cannot participate in the physical development, it is unnecessary that the protective layer be of a material which is substantially impermeable to the components of the physical developer during the development, which may require considerable time.

On the other hand, the material of the protective layer must be opaque to ultra-violet light and for this purpose we use, for example, polystyrol or an acetyl-cellulose layer containing a substance by which ultra-violet rays are absorbed,.such as ultra-violet light is also utilized for the repro-- duction or copying this can be effected immediately after the coloring of the track and without removal of the protective layer.

Example. 8.-Th e layer of lead acetate and gelatin provided according to Example 1 may be 5 exposed before application oi the protective layer,

i. e. during the manufacture of the carrier, and this may be done in the following Ways:

Example 8A.-'I'he mass of lead acetate and gelatin to be. used for the recording layer is exposed prior to being applied to the supporting layer.

Example 8B.--The layer of lead acetate and gelatin is formed upon the supporting layer and is then exposed, and if required, a protective layer is applied.

' 1n Examples 8A and 8B, the protective [layer does not need to be impervious to the type of light required for the physical development because the mass of the recording layer has been exposed prior to the applicationof this layer. On the other hand, the material of the protective layer must be transparent to the light used in reproduction and must be substantially impervious to the components of the physical development.

Example 8C.-The layer of lead acetate and gelatin is formed on the supporting'layer and after a protective layer is applied, Ais exposed through the protective layer. The latter layer must, of course, be transparent to the. type of light utilized for the physical development and for the optical reproduction.

Theoreticallythe method of Example '7A would insure a greater sharpness of the edges of the colored track than at the methodsdescribed inA precious metal nuclei suchas silver nucleibwhichl may be eiected by adding a colloidal silver solution to the mass' of lead acetate and gelatin.

Example 10.-According to the invention, in-

stead of using a physical ldevelopment,a normal chemical development may be used. In this case the recording layer should' preferably consist of a is impervious to the ultra-violet light that is used prior to the development.l

While we have described our invention with reference to specific examples and applications, We do not wish tobe limited thereto but desire the appended claims to be construed as broadly as permissible in view of the prior art.

What we claim is:

1. A method of rendering optically-reproducible by chemically coloring a vibration track mechanically-recorded in the recording layer of a carrier, comprising the steps of introducing a.

, molecularly-dispersed substance Within said regrainless silver bromide emulsion which may be incorporated in the recording layer during its manufacture. -On the other hand, the silver bromide may be formed in the recording layer after.

the track has been cut,'for example by causing a silver nitrate solution to act on a. colloidal layer containing halogen ions. The layer may be given the capacity of being chemically developed by means of a suitablel exposure which may take place either before or after recording. The various possibilities of realization according to the examples described under 7, 8, 8A, 8B arid8C may also be realized in this case. Y

If the silver bromide is incorporated in 4the recording layer during the manufacture of the carrier, i. e. before the protective layer is applied, and if the step of rendering itdevelopable has to be effected after the oscillation track has been provided, care should be taken to insure that, with respect to the absorption of light, .the protective layer is of a material which is opaque to the light used prior to the development, but is transparent to the light used yfor optical copying or for reproducing. For-this purpose we form the protective layer, for example, of polystyrol and quinine sulphate. Such a layer transmits infra,- red reproduction light and blue copying light but cording layer, applying a suitable thin protective layer to the surface of said recording, layer, and applying to the surface of the track after the recording a second substance capable of cooperating with said first substance to produce a colored product.

2. A method of producing a colored vibration track in a carrier having a recording layer provided with a molecularly-dispersed substance, comprising the steps of mechanically-recording the track in the recording layer, forming a protective layer at the surface of the covering layer bounding the track, and forming colored material in a surface portion of the track by applying to the surface a substance capable of chemically reacting With the molecularly-dispersed substance With the production of colored material.

3, A method of producingA a colored vibration trackin a carrier having a recording layer provided with a colloidally-dispersed substance, coming the track, and forming colored material in a surface portion of the track by applying to the.

surface a substance lcapable of chemically reacting with the colloidally-dispersed substance with the production of colored material.

4. A method of rendering optically-reproduc- 4 ible by chemically coloring a vibration track mechanically-recorded in the recording Vlayer of a carrier, comprising the steps of introducing a colloidally-dispersed substance within said recording layer, applying a suitable thin protective layer to the surface of said recording layer, and applying to the surface of the track after the recording a second substance capable of cooperating with said first substance to produce a colored product.

5. A method of rendering optically-reproducible by chemically coloringl a 'vibration track me- V chanically-recorded in the recording. layer of a carrier, comprising the steps of introducing a molecularly-dispersed substance within said recording layer, applying a suitable thin protective layer to the surface of said recording layer, and applying to the surface of the track afterA the recording a substance capable of chemically rejacting with said first substance to form a colored layer to the surface of said recording layer, and j appyling to the surface ofthe track after the recording a substance capable of chemically .re-

acting with said first substance to form a colored product atv the surface of the track by a purely chemical reaction between said substances. 7. A methodvof rendering optically-reproducible by chemically coloring a vibration track meible a vibration track mechanically-recorded in the recording layer of a carrier, comprising the steps of placing within said recording layer a molecularly-dispersed substance, applying a suitable thin protective layer to the surface of said recording layer, and applying to the surface of the track after the recording a second subtsance capable of forming a colored insoluble compound y within a surface portion of the track by a purely chemical reaction with said rst substance.

9. A method of rendering optically-reproducible a vibration track mechanically-recorded in the recording layer of a carrier, comprising the steps of placing within said recording layer a colloidally-dispersed substance, applyinga suitable thin protective layer to the surface of said recording layer, and applying to the surface 'of the track after the recording a second substance carrier, comprising the steps of introducing a molecularly-dispersed substance into said recording layer after the recording of the track, subse- .quently applying a suitable thin protective layer to the surface of said recording layer bounding the track, and. applying to the surface of the track a second subtsance capable-of chemically y reacting with said rst substance to form a colred product within a surface portion of the rack..

11. A method of rendering optically-reproducible by chemically coloring a vibration track rilechanically-recorded on a carrier having a recording layer, comprising the steps of introducing into said recording layer a colloidally-dispersed subtsance after the recording of the track, sbsequently applying a suitable thin protective layer to the surface of said recording layer, and applying to the surface of the track a second subv stance capable of chemically reacting with said first substance to form a colored product within a surface portion of the track.

12. A method-of rendering optically-reproduc-` ible a vibration track mechanically-recorded in the recording layerof a carrier, comprising the steps of placing a substance within said recordi the vsurface of said recording layer, and applyingl after the recording a sulphide solution to the sur.v

face of the track to form a colored sulphide substantially free from deleterious 'graininesa 14. A method of rendering opticallyfreproducible a. vibration track mechanically-recorded in the recording layer of a carrier, comprising the steps'of placing a metal compound in molecular dispersion within said recording layer, applying a suitable thin protective layer to the surface of said recording layer, and applying after the recording a reducing agent to the track to reduce :said compound and form at the surface of the track a colored layer substantially free deleterious graininess.

15. A method of rendering optically-reproduc' ible a vibration 'track mechanically recorded in the recording layer of a carrier, comprising the -steps of incorporating a metal compound in molecular dispersion vwithin said recording 'layer prior to the recording, applying a. suitable thin protective layer to the surface of said recording layer, and applying after the recording a reducing agent to the surface of the track to reduce said metal compound and form at the surface of the track a colored layer substantially free from deleterious graininess.

16. A method of rendering optically-reproducible a vibration track mechanically recorded in theA recording layer of a carrier, comprising the steps of placing a photo-chemically-sensitive metal compound in molecular dispersion within said recording layer, exposing the surface of the track to actinic light, applying a suitable thin protective layer to the surface of said recording layer, and developing the exposed'metal comfrom pound after recording to form at the surface of the track a colored layer substantially free from deleterious graininess. v

4 17. A method of rendering optically-reproducible a vibration track mechanically recorded in the recording' layer of a carrier, comprising the steps of forming by means of a.chemical reaction a photochemically-sensitive metal compound inmolecular dispersion within said recording layer, exposing the surface of the track to actinic light, applying a suitable thin protective layer to the surface of said recording layer, and developing the exposed metal compound after recordingto form at the surface of the track a colored layer substantially free from deleterious graininess.

18. A method of rendering optically-reproducible a -vibration track mechanically recorded in the recording layer of a carrier, comprising the steps 'of forming by means of a chemical reaction a photochemically-sensitive metal compound in colloidal dispersion Within said recording layer, exposing the surface of the track to actinic light, applying a suitable thin protective layer to the surface of said recording layer, and developing the exposed metal compound after record- Iingy to form at the surface ofthe track a colored layer substantially free from deleterious 19. A method-of rendering optically-reproducible a vibration track mechanically recorded fin the recording layer of a carrier, comprising the steps of placing a 'photochemically-s'ensitive metal compound in molecular dispersion within -said recording layer, applying to the surface of said recording layer a suitable thin protective layer opaque to a predetermined light, photochemically decomposing the metal compound at the track surface with actinic light to which said protective layer is opaque, and applying after recording a developing substance to form at the track surface a colored layer substantially free 'substance in at least the portion of the recording layer forming the track, and chemically forming colored material within said portion of the recording layer by applying to the surface of the track a' second substance capable of chemicallyreacting with the rst substance with the production of colored material.

21. In the manufacture of optically-reproducible vibration records on a carrier having a recording layer and a thin protective layer and provided with a vibration track which is bounded by portions of the protective layer and whose surface is formed substantially by the recording layer, the steps of placing a colloidally-dispersed substance in at least the portion of the recording layer -forming the track, and chemically forming colored materialwithin said portion' of the recording layer by applying to the surface of the track a second substance capable of chemically-reacting with the first substance with the production of colored material.

22. A method of rendering optically-reproducible a vibration track mechanically-recorded in the recording layer of a carrier, comprising the steps of placing a metal compound in colloidal dispersion within said recording layer, applying a suitable thin protective layer to the surface of said recording layer, and applying after the recording a reducing agent to the track to reduce said compound and form at the surface of the track a colored layer substantially free from deleterious gralniness.

23. A' method of `rendering optically-reproducible a vibrationltrack mechanically recorded in the recording layer of a carrier, comprising the steps of incorporating a metal compound in colloidal dispersion within said recording layer prior to the recording, applying a suitable thin protecf tive layer tothe surface of said recording layer.

and applying after the recording a reducing agent to the surface of the track to reduce said metal compoundA and form at the surface of the'track y a colored layer substantially free from deleterious graininess.

24. A method of renderingv optically-reproducible a vibration track mechanically recorded in the recording layer of a carrier, comprising the steps of placing a photochemically-sensitive metal compound in colloidal dispersion within said recording layer, exposing thesurface of the track to actinic light, applying a suitable thin protective layer to the surface of said recording layer, and developing the exposed metal compound after recording to format the surface of the track a colored layer substantially free from deleterious graininess. y

25. A method of rendering 'optically-reproducible' a vibration track mechanically recorded in the recording layer of a carrier, comprising the steps of placing a. photochemically-sensitive metal compound in colloidal dispersion -within .said recording layer, applying to the surface of said recording layera suitable thin protective layer opaque to a predetermined light, photochemically decomposing the metal compound at the track surface with actinic light to which said protective layer is opaque, and applying after' recording a developing substance to form at the track surface a colored layer substantially free from deleterious graininess.

JAN HENDRIK DE BOER. CORNELIS JOHANNES DIPPEL. 

